Grinding-machine and method of grinding



F. MLLER.

GRINDING MACHINE AND METHOD 0F GRINDING.

APPLICATION FILED JMLZT. 19|?.

Patented Jan.

EI l.

I0 SHEETS mm MM P Tdv TTORNEY Patnted Jan. 11, 1921.

I0 SHEETS-SHEE 2- Y `nwmrofr F. a M.

" y my 4 URNEI F. MLLER.

GIIINDING MACHINE AND METHOD 0F GRINDING.

APPLICATION FILED MN.27, |911.

\ F. MLLER.

GRINDING MACHINE AND METHOD 0F GRINDING.

PPLICATRUN FILED IMLZI, 1917. ll'

I0 SHL'ElS-SHEEI 3.

.am Y lilik@ mmm INVENTOR F. I E

sr -f' i gamers F. MULLER.

GRINDING MACHINE AND METHOD 0F GRINDING.

PPUCATION FILED JILZ. 'gl'. 1,365,337. Patented Jan. 11,1921.

l0 SHEETS-SHUI 4'.

INVENTR Enma/Wam F. MLLER.

GRINDING MACHINE ANU METHOD 0F GRINDING.

APPLICATION FRED MM2?. 1917. 1,365,337. Patented Jan. 11, 1921.

10 SHEETS-SHEEI 5.

mmm l F. MLLER.

GRINDING MACHINE AND METHOD 0F GR|ND|NG.`

APPLICATION FILED JAN.2?, 1911.

Patented Jan. 11, 1921.

SHEETS-SNES! G- F. MLLER.

GRINDING MACHINE AND METHOD 0F GRINDING.

Patented Jan. 11, 1921.

APPLICATION FILED IAN.2| I9|7.

F. MLLER.

GRJNDXNG MACHINE AND METHOD 0F GRINDING.

APPLICATION FILED IAN-27,1%?. 1,365,337. Patented Jan. 11. 1921.

l0 SMEEYS-SHEEI 8.

mrshfvron -www Si F. MLLER.

GRINDING MACHINE AND METHOD 0F GRINDING.

l.. 2 L 9 1 E L m 1 L, w w msm S O. h2 .J w. w .w w HL., t 4% m @NQ mi m kx M m m m .n .mf Y EJrL 3 m i 5, 6 Su l 3 lr 1 HVVENTUH Fwuay MM 4F. MULLER. GRINDING MACHINE AND METHOD 0F GRINDING.

FPLICTIDN FILED IAILZ, |911. 1,365,337. Patented Jan. 11

and from the wheel whi to present the UNITED STATES PATENT oen-CE.

FBIEDERICH ILLEB, 0F HARTFORD, CONNECTICUT, ASSIGNOB T0 PRATT 0: WHIT. NEY COMPANY, 0F HARTFORD, GONNECTICUT, A OOBPORATION 0F NEW JERSEY.

GBINDING-IACHINE ANI) METHOD 0F GBINDING.

Specication of Letters Patent.

Patented Jan. 11, 1921.

Application led January 27, 1917. Serial Ro. 144,923.

To all 'whom itmay concern.' f

Be it known that I, FniEnEnIoH MLLER, a citizen of the United States residing at Hartford, in the county of Ilartford and State of Connecticut, have invented certain new and useful Improvements in Grinding- Machines and Methods of Grinding, of which the following is a specification.

The invention relates particularly to metal working machines or attachments therefor adapted for finishing and relieving the flutes or teeth of reamers or other similar metal working tools. particularly useful when applied to inachines provided 'fwith Grinding wheels, but as concerns some of t e less specific features, it can be used in connection with machines provided with other metal reducing means such as cutting tools. It will appear, however, from the following specification that the invention, as concerns some of its more specific features, is adapted only for grinding machines.

The'invention also relates to an improved method of grinding reamers and similar tools.

Throughout the specification reference will be had toa grinding machine and a grinding wheel, but in many cases these terms nreusedsimply for convenience and for brevity of expression and are intended to include other metal reducing means as set forth above. Also throu hout the specification the. term reamer will be used, but it will be understood that the term is used generically and is intended `to include other metal Working tools having teeth or flutes adapted to be relieved, particularly by grindin One of le objects of theV invention is to provide n mechanism for presenting the teeth of a reamer toa grinding wheel in rapid succession 'for relieving the wheel engaging each tooth along its entire length. The desired relief is most advantageously effected by reciprocati e itis being turned successive teeth. Preferably a relative feeding is effected between ,the

l-reamer and cause them to approach each other vunti the the wheel vduring grindin teeth have been reduced to the desired form and size. i

A further object of the invention is to provide improved mechanism whereby the The invention is the reamer toward.

amount of relief can be changed as required.

A further object of the invention is to provide lmprovedmeans for turning or` rotating the reamer, the said means being adapted` to resent a different tooth to the grinding w eel at each reci rocation notwithstanding variations in t e spacing of the teeth.

Another object of the invention is to provide numerous improved structural features adapted for carrying out the purposes already set forth.

Another object of the invention is to provide an attachment for a rinding machine, the attachment being a apted to cm operate with the grinding wheel and other parts of a previously or se arately constructed. machine to accomplis the results above set forth.

Another object of the invention is to provide an improved method of grinding a reamer, whereby all of the teeth are relieved and finished from end to end substantially simultaneously.

Still furtherobjects of the invention will be ap arent from the following specification and t e claims. i' t A I have shown two different mechanisms each embodying certain of the structural features of my invention and each adapted for carrying out my improved method, but it is to be understood that the structural features of my invention can be embodied in mechanisms different from those shown `and that the improved method can be foltiona view of 'a mechanism em dying many of the features of the invent1on.

Fig. 2 is a 'horizontal sectional view of the mechanism shown in Fig. 1.

Fig. 8 is an end view of the headstock shown in Figs. 1 and 2, this view being taken from the left.

Fig. 4 is a transverse vertical sectional view taken along the line 4-4 of Fig. 2.

Fig. 5 is a transverse vertical sectional view taken along lthe line 5--5 of Fig. 2.

Fig. 6 is an end View of the headstock taken from the right.

Fig. 7 is an enlarged detail view of a part of the mechanism for turning the reamer.

Fig. 8 is a transverse sectional view of the tailstock taken along the line 8-8 of Fig. 2.

Fig. 9 is an end view of the tailstock, the view being taken from the right.

Fig. 10 is an end view of the reamer clamping device, the view being taken from the right.

Fig. 11'is a fragmentary vertical sectional View taken along the longitudinal center line of the mechanism.

Fig. 12 is a diagrammatic view showing the principal element of the reamer actuating`mechanism.

ig. 13 is a vertical longitudinal view similar to Fig. 1 but showing another embodiment of the invention, the mechanism shown being adapted tb be substituted for the mechanisn shown in Figs. 1 to 12.

Fig. 14is a horizontal sectional view of the mechanism shown in Fig. 14.

Fig. 15 is an en d view of the headstock shown in Fi 13"and 14, the view being taken from t e left.

Fig. 16 is a transverse vertical sectional view taken along the line 16-16 of Fig. 14.

Fig. 17 is a transverse vertical sectional view of the tailstock taken along the line 17-17 of Fig. 14.

Fig. 18 is anend view of the tailstock, this view being taken from the right.

Fig. 19 is a plan view (with parts ref moved) of a complete grinding mechanism embodying the invention.

Fig. 20 is an end view taken .from the ri lit.

ig. 21 is a combined sectional and end view taken along the line 21-21 of Fig. 19.

Figs. 22 and 23 are detail views showing in dierent positions the essential parts of the mechanism fol-controlling the. osition' of the carriage sup orting the grin 'ng Wheel.

Fig. 24 is a ragmentary sectional view taken along the' line 24-24 of Fig. 21.

Fig. 25 is a` fragmentary sectional view taken along the line 25e-25 of Fig. 19, some of the parts beingshown in elevation.

Fig. 26 is a agmentary sectional view taken along the line 263-26 of Fig. 19, some of the parte being shown in elevation.

Referring tothe drawings, 1 represents as a whole a reamer` holding and actuating mechanism adapted to coperate with a grinding wheel 2'. The mechanism 1 may be and preferably isl constructed as an attachnient adapted to be appliedeto a grinding.

incassi ySo far as illustrated in Figs. 1 to 12 the grinding machine comprises, in addition to the Wheel 2, a bed 3 having longitudinal ways 4 and 5 and longitudinal T-slot 6. The reamer holding and actuating mechanism comprises a headstock 7 and a tailstock 8 and preferably other devices mounted upon or adapted to be mounted upon the bed.

The headstock 7 and the tail stock 8 are provided respectively with centers 9 and 10 adapted to engage the respective ends of a reamer R. The headstock and tailstock are preferably adjustable along the Ways 4 and 5 of the bed 3 in order to accommodate reamers of different lengths. Suitable means such as bolts 11 and 11 entering the T-slot 6 are provided for holding them. in adjusted positions.

The machine is so constructed that rela tive reciprocation of the reamer holding devices and the grinding wheel toward and away from each other can be effected, this reciprocation being of theproper amplitude to effect the desired relief of the reamer teeth. So far as certain of the broader features of the invention are concerned, it is immaterial whether the grinding wheel be reciprocated towardor from the reamer, or the reamer reciprocated toward and from the grinding wheel; but morder to carry out some of the more specific purposes of the invention it is necessaryr to reciprocate the reamer toward andv from the wheel. The provision of means for reciprocatin the reamer is especially important when t e invention'is embodied as an attachment for a machine not otherwise adapted for relieving.

The reciprocaton of the reamer is elected by moving the centers 9 and 10, the movement pre erably being an oscillator one about an eccentric lon itudinal axis. cans are provided for oscil ating both of the centers in unison, and reference will first be had to the mechanism for oscillating the center 9 of the headstock.

Mounted in suitable bearings 12 and 13 in the main frame casting of the headstock is a spindle 14, this spindle being providedwith V a longitudinal eccentric aperture 15 the forward Vend of which is tapered to receive thecenter 9.` Preferably the axis of the aperture is normally approximately in the saine vertical plane as the axis of the spindle, and

Leanser which are mountedtight and loose belt pulleys 17 and 18.4 For shifting the belt from one to the other of these pulleys there is rovided a manually operable shifting ever 19.

A longitudinal rotatable shaft 20 is mountedlin suitable bearings near the bottom of the headstock casting. At the end of the head stock there is provided a` train of gearing for connecting the drive shaft 16 and the shaft 20. As shown, this train of gearing 'comprises a pinion 21 mounted on the shaft 16 and meshing with a gear 22 mounted on a stud 23 carried by the headstock castin Secured to the gear 22 is a pinion 24 w ich meshes with an idler gear 25 on a stud 26 also carried by the headstock castin The idler gear 25 meshes with a gear 2 secured to the shaft 20. By means of this train of gearing the shaft 2O is rotated at a speed considerably less than that of the shaft 16.

Keyed to the shaft 20 is a collar or bushing provided with a cam 28. Pivoted to the headstock casting at 29 is a lever 30 provided with a roller 31 positioned to engage the cam 28. Secured to the spindle 14 is a lever 32 positioned abovethe lever 30. Carried by the lever 32 isa 1u 33 which is V-shaped at its bottom and which engages the lever 30. The lug 33 is adjiistable longitudinally of the .lever32 and can be secured in adjusted position by means of a set screw 34. A .coil spring 35 presses downward upon the lever 32 thus serving to hold the lug 33 firmly 1n engagement with the'lever 30. The upper end of the spring abuts against a screw 36\ which can be adjusted to change the spring rassure. A

It wil be' seen that as the shaft 20 and thecam 28 are rotated, the lever 30 will be oscillated about its pivot, and by means of thelug 33 will transmit an oscillatory movement to the lever 32 and the spindle 14. The extent of the oscillatory movement can be changed by moving the lug 33. It will b e seen that when the lug is moved to the right as viewed in Fig. 4, 1t engages a point on the lever 30 where the vertical-movement is less, and at the same time the effective length of the lever 32 is increased, thus still further decreasin the amplitude of oscillation. When the dug is moved to the left the opposite results are obtained and the amplitude of oscillation is increased.

Because of the eccentricity of mountin of the center 9 the -oscillation brought a utin the wa described causes the center to oscillate a ut the spindle axis,thus eiecting a reciprocation toward and from the grlnding wheel.

As shown in Fig. 4, the roller 31 is in engagement with the lowest part of the cam 28. In this position' the, leyers: 30 and 32 are parallel and the axis. ,of the aperture 15 and of the center 9 is directly below the axis of the spindle 14. The axis of the center is in its outermost position and any movement thereofmust be toward the right or away from the grindn wheel. It will be clear that because of t levers \30 and 32 are arallel for this position, the lu 33 can e adjusted to change the amplitu e of oscillation without changing the outermost position of the axis of the center.

The center 10 of the tailstock is carried by an oscillatory spindle which is Tprefera ly in the form of a segment 37. e segment- 37 is `mounted upon the main tail- `stock casting which is provided with a semicylindrical recess adapted to receive it. The segment is provided at its ends with semicircular undercut rabbets and semi-circular gibs 38 and 39 are secured to the tailstock casting, fittin the rabbets and holding the segment in p ace Without interfering with oscillatory movement. Preferably, as shown inFig. 8, the segment 37 extends through only a little more than 180, thus leaving the space beyond the axis substantially unobstructed and adapted to be occupied by the grinding wheel when necessary.

The center 10 is preferably connected with the oscillator segment 37 by means of a slide 40 to w ich the oenteris rigidly secured. The center is eccentrically positioned with respect to the axis of the segment, the eccentricity being the same in extent and position as the eccentricity of the center 9 with respect to the axis of thespindle 14. The slide is longitudinally movable with res ect to the segment, and means are provided for applying a redeterminedly limited pressure to the s ide to move it. As shown, the movement of 'the slide toward the tailstoclk is effected by a coil sprin 41, and in the other direction by a rod 42 w ich extends through the spring. ne end 'of the spring abuts against a stop 43 secured to the segment 87, and the rod 42 extends through an aperture in this stop. Mounted on the rod 42 is a grooved collar 44, the

osition of which is adjustable by means of ook nuts 45. Normally the slide is moved toward the left by means of the spring, the extent of movement bein limited by the rod 42 and the collar 44. ivoted on the tailstock casting is a manually operable lever 46 provided with pins 47, 47 engaging the oove of the. collar 44. By means of the ever 46 which acts through the collar 44 and the rod 42, the slide 40 can be drawn Jhack against the pressure of the spring 41. In-this way the center 10 anfbe withdrawn to release a reamer or other tool which may have been held between it and the centers 9 and to permit another reamer to be ut in place; As soon as the lever 46 is re cased, the Aspring 41 presses the centerA 10 against e fact that the the reamer with a limited predetermined pressure.

For oscillating the segment 37 there is provided a mechanism similar to that rovided for oscillating the spindle 14. he shaft 20 is extended to engage suitable bearings in the tailstock casting. Connected with the shaft is a collar or bushing provided with a cam 47. This cam bushing is splined to the shaft so as to permit the tailstock to be adjusted longitudinally with respect4 to the headstock. ivoted to the tailstock casting at 48 is a lever 49 provided with a roller 50 engaging the cam 47. Secured to the segment 37 is a lever 51 which carries a lug 52 V-shaped at its bottom and engaging the lever 49. The lug is adjustable longitudinally of the leverI and can b'e held in adjusted position by means of the set screw 53. A spring 54 presses downward u on the lever 51, the pressure of the spring eing ad'ustable by means of the screw 55. It will be seen that by means of this mechanism the segment 37 will be oscillated as the shaft 2O and the cam 47 are rotated, the extent of oscillation being adjustable by changing the position of the lu 52.

. grinding wheel.

'reamer mounted on the centers and for turning 1t in such a way that successive As shown in ig. 8 the roller 50 is in engagement with the lowest part of the cam 47. In this position the levers 49 and 51` are parallel and the axis of the center 10 is directly below the axis of the segment 37. The axisof the center is in its outermost posit-ion and any movement thereof must be toward the right or away from the `It will be clear that because of the fact thatthe levers 49 and 51 are parallel for this position the lu 52 can be .adjusted to change the amplitu e of oscillation without changing' the outermost position of the axis of the center.

The levers 49 and 51 are respectively similar in length and position to the levers 30 and 32 and the two cams 28 and 47 are similar in shape and in position on the shaft 20. Therefore when the lugs 33 and 52 are similarly ositioned the two centers 9 and 10 are oscillated in unison and to the same extent. Preferably as indicated in Fig. 2 suitable marks are provided on the levers 32 and 51 so that the two lugs 33 and 52 can be readily positioned so' as to obtain the same amplitude of oscillation for the two centers.

Mechanism is provided for engaging a teeth are presented for grinding at successive movements or oscillations of the reamer toward the grinding wheel. The turning may be either continuous or intermittent. If the reamer to be ground has its teeth uniformly spaced, then the turning may be not only continuous but ata uniform rate.

However, if the teeth of the reamer are' unevenly spaced, it isnecessary to vary the rate of turning in such a way as to compensate for the uneven spacing. Obviously,' whether the turning be continuous or intermittent or at a uniform or a variable rate, it is necessary in order to effect a relieving of the teeth to turn the reamer simultaneously with and in definite relation to its movement toward or away from the grindin wheel.

f prefer to e'ect the turning intermittently and in order that the machine may be capable of grinding reamers having their teeth unevenly` spaced, I prefer to rovide a turning mechanism as shown in igs. 1, 2, 5, 6 and 7. Rotativel mounted on the spindle 14.- concentrical y with the center 9 and eccentrically of the bearin s 12 and 13, is a sleeve or bushin 56 provi ed at 57 with gear teeth. `Secured to the sleeve 56 is an arm 58 carryin a' pin 59 which extends parallelly with ie spindle 14 and projects through an arcuate slot 6() in the wall of the headstock. Preferably there is provided a supplemental arm 61 also engagin the pin 59 and havin abearing on the spindle concentric with t e center. Secured to the pin 59 is a bracket 62, this bracket preferably being adjustable along the pin and. held in place by a set screw 63 engaging a groove 64 in the in. Connected with the bracket 62 is a Slide 65 (see Fig. 7) adjustable horizontally toward and awayfrom the vertical plane of the spindle axis. By means of a bolt 66 the slide can be secured to the bracket in any desiredposition. The forward end ofthe slide is forked and -between the forks there is `pivoted a block `tween the slide and t e block, serving to press the lower end of the block forward and to swin the upper end of the pawl inward towar the axis of the center. The pawl 68 is adapted to engage one lof the teeth of a reamer. (see Fig. 12), and when the sleeve 56 and the parts carried thereby 115 including the pawl, are turned in the direction of the arrow, the reamer is turned or advanced. After a predetermined amount of turning the sleeve 56 and the arts carried thereby are turned in the ot er direction, the awl' 68 slipping over the next tooth of t e reamer and dropping in behind it.

For oscillating the sleeve 56 the follow-4 ing mechanism is rovided. Mounted upon the shaft 20 isa s eeve orbushing provided `with a cam 72., Pivoted to the headstock .The end of the leverf76 is .provided with a segmentall gear 82 meshing with a pinion 83 rotatable upon a pin 84 mounted 1n the headstock casting.` (Jonnected with the pinion 83 is a segmental gear 85 meshing with` the teeth 57 of the sleeve 56. It will be seen that 'by the mechanism described an oscillatory movement is transmitted to the sleeve@I 56 and to the ,parts carried thereby whei the shaft 20 and the cam 72 are rotate The cam 72 is so shaped and so positioned with respect to the cams 28 and 47 that the movement of the pawl 68 in the direction. te advance the reamer is completed when the reamer 1s moving awayV rom the grinding wheel. This will be apparent from an inspection of the diagrammatic view in Fig. 12, it being understood lthat the cam 47 and the parts operable thereby are movable in unison with the cam 28 and the parts driven thereby (which are illustrated). l The roller 31 -is in engagement with an intermediate part of the cam 28 and is being pushed upward, and the part of the cam The cam 72 in rotatrmg to its present position has moved the lroller 75 upward and has caused the pawl 68 to rotate thereamer in the direction of the arrow. The cam 28 in rotating to its present position has moved the roller 31 u ward, thus turning the spindle 14 in te clockwise direction and bodily moving the this way the reamer has been turned and reamer away from the grinding wheel. 'In

at the same time moved `away from the wheel, the tooth adjacent the y'wheel being ground with the proper relief.` Further ro- I tation ofthe cam 28 moves the rea-mer entirely out of engagement withthe wheel, thus preventing an possible improper grinding thereof. is t e cam 72 continues to rota-te the roller 75 is permitted to move downward under the influence of gravity and of the spring 80, thus moving the pawl 68 in the clockwise direction and causing it't' take a Igosition back of the next reamer tooth. uring the subsequent movement of the reamer in -the direction of the arrow the roller 31 is permitted by the sharply inclined section 28 of the cam 28 to move quickly downward and swing the reamer outward so as to be ready for the grinding of the next tooth.

78 the By changing the position of the lug 68 can amplitude of oscillation of the paw ement with the highest be changed as already described. The amplitude of oscillation may be varied to correspond approximately with the spacing of the reamer teeth, and in any case the adjustment must be such that the pawl moves backward a little beyond the next tooth to make sure of engagement therewith. When the reamer teeth are unevenly spaced the amplitude of oscillationmust be adjusted for the maximum distance between any two adjacent teeth. The pawl 68 is so adjusted with respect to the block 67 that at the end of its movement forward and u ward vits upper end liesL in a horizontai) plane passing through the axis of the grinding wheel and the axis of the reamer. This position is reached when the roller 75' is on the highest parallel. Therefore the extentof forward movement of the "cam is not affected in any way by the adjustment of the lug 78 to change the amplitude of oscillation.

It is desirable to provide for changing the amount of relief as may be required for different classes of work. Heretofore in the case of eccentrically mounted oscillating centers the amount of relief has been changed by changing the eccentricity, In accordance with-my invention the mechanism is greatly simplified by providing oscillating centers hav1ng.their eccentricity fixed, and by providing other means for changing the amount of relief. When the rate or the manner of turning is fixed or redetermined, the amount of relief can be ciianged by changing the amplitude of oscillation. In the resent construction this 'is elfected by changing the positions of the lugs 33 and 52, as already described. For a given speed of the shaft 20 the time required for each com lete cycle of oscillation -is fixed and there ore, when the rate of turning isfixed as above stated, there will be a definite amount of turning for each cycle of oscillations. By changing the amplitude the amount of movement of ,tionfixed theV amount of movement toward or from the grinding wheel is fixed, and if e amount of turning during such movement be chan d, the amount of relief will be changed. f the rate of turning be rapid the angle of relief is small, and if the rate of turning be slow than the angle of relief is lar e. In the present construction the rate o turning may be changed by changing the amplitude of oscillation ofthe pawl 68. For a given speed to the shaft 20 the time required for each complete cycle of. oscillation of the pawl is fixed and therefore the an ar s eed is increased or decreased as t e amp itude is increased or decreased.

In u`sin the machine as so far described and in fo owing the method constituting a 'part of my invention, the headstock 7 and tailstock 8 are adjusted on the bed 3 to position the centers 9 and 10 at the correct distance from each other to properly engage reamers of the lengthto be ground and to brin the teeth of the reamers opposite the grin ing wheel 2. Then the center 10 1s rawn back by means of the lever 46 and a reamer is put in place.- The lever is released and the center 1() is pressed against the reamer by the spring 41'. Care is taken in preliminarily adjusting the headstock and tailstock and inputting the reamer in place to see that the teeth face downward at the rear so as to be properly engaged by the pawl 68. For a right-hand reamer the shank must engage the center 10 and for a left-hand reamer the shank must enga-ge the center 9. p

After the reamer is properly engaged by the centers the drive belt is shifted to the pulley 17. The pawl 68 then acts to turn the reamer intermittently tooth by tooth and each tooth is round as it is resented to the grinding w eel. As alrea y stated, the reameris at theposition farthest away from the wheel when the per-position as shown in ing the edge of the tooth engaged by the pawl` to be higher than any other part of the tooth. Duringl retrograde movement of the pawl the reamer is moved a little farther away from the grinding wheel to in-i sure clearance. When the y pawl `has engaged the next tooth and has started to turn 1t, the reamer is caused to move quickly toward the inding wheel, the wheel entering the space etween the two teeth. turning movement of the reamer continues the reamer is again moved away from the wheel at a spec so related to the speed of turning as to elect the grindin of the tooth with t e proper convex relie surface. It will be seen that each tooth engages the grinding wheel but once for each revolution of the reamer, successive teeth. being presented for grinding at successive oscillations. After the grindin has been completed, the center 10 can withdrawn to release the reamer and another reamer to be ground can be put in place. k

Inasmuch as the turning 'of the reamer is ei'ected b engagement with( the reamer teeth, it wil be clear that the turning will be properly effected even though the teeth may be unevenly s ced. It is only neces. sary to so adjust t e parts that the throw of thepawl is at least as-great as the greatest distance between any two adjacent teeth. For teeth that are more closely spaced the awl is in Vits upig. 12, thus caus-` As the" of the teeth, all of the teeth being accurately ground and with theirV cutting edges atthe same distance' from the center.

Under some vcircumstances there is a tendency for the reamer to move backward with the pawl 68 when the pawl is moved backward to engage the next tooth. Inorder to prevent this and to hold the reamer stationary as concerns rotary movement during the backward movement of the paw1,.I prefer to provide a 'mechanism for 'engaging the reamer, this mechanism preferably acting frictionally. As shown in Figs. 1, 2 and 10, there is provided a bracket 86 resting upon the bed 3 and adjustably secured thereto by means of the bolts 87 enterin the T-slot 6. This bracket is provided wit an a I'ture through which the shaft 2O extends. ounted on the bracket 86 is a transversely movable horizontal slide 88. This slide is rovided with a handle 89 by means of W ich it may be moved, the amount of movement being adjustably limited by means of the screw 90 secured to the slide and the bolt 91 secured to the bracket and havin Stop nuts at 92. The horizontal slide 88 1s provided with vertical ways in which are mounted two vertical slides or blocks 93 and 94, these slides being controllable b the oppositely threaded screw 95. en the screw is turned in one direction the slides will be moved away from each other and when the screw is moved in the other direction the slides will be moved toward each other. The two slides are at all times uidistant from a common center line. ivated to thevertical slide 93 is a horizontal lever 96, and pivoted to the vertical slide 94 is a horizontal lever 97. At the forward ends of these levers are friction pads 98. Slidably mounted in lugs on the lever 97 is a push rod 99 engaging an arm 100 extending verticall from the lever 96. A spring 101 surroun s the rod 99 and serves to press it outward against the arm 100, thus tending to force' tofward each other the ends of the levers carrying the friction pads.

In'use, the bracket 86 is adjusted along the bed so as to be in position to engavhe shank of the reamer being ground. ile the reamer is being put into placethe slide is drawn back manually and then when the to be mounted upon the be reamer is engaged by the centers the slide is pressed forward, the friction padssprin ing apart to pass over the shank. The shan is gripped between the pads with suflicient force to prevent any accidental backward movement of the reamer, the force being insuicient, however, to interfere in( any way with the normal advancing movement.

When it is required to grlnd only reamers having evenly spaced teeth, it is possible to .make use of a mechanism somewhat simpler than that already described, but nevertheless similar in man1? respects. Such a mechanism is shown in igs. 13 to 18. It Awill be understood that the construction shown in these iigures is intended to be used alternately with the construction shown in Fi 1 to 12, and that the other parts of the mac ine may be and preferably are the same as a1- ready briefly described. It will. furthermore be understood that the mechanism shown in these figures may be constructed as an attachment for a reviously or separately constructed mac ine, or 1f desired, may constitute a permanent part of a complete machine.

The mechanism comprises a headstock 7 and a tailstock 8'L mounted u on or adapted 3 and held in lace by means of bolts 11" and 11 enterlng the T-slot' 6. Carried respectlvely by the headstock 7 and the tailstockA 8* are centers 9* and 10". The center 9 is mounted in a s indle 14* by means of a collet 102 contro led by a spring 103 surrounding arod 104. 'B means of a lever 105 pivote at 106 the co let can be moved to the right in oppositionl to the spring to release the center. i

Abushing 107 is rotatably mounted yin the headstock casting and the central aperture of this bushing is formed eccentrically.-

The spindle 14Il is rotatably mounted in the eccentric aperture of the bushing. As shown in Fig. 16 the axis of the spind e 1s directly above the axis of the bushing.

Means are provided for oscillating the bushing 107 and in this way oscillating the axis of the s indle .14* and of the center 9*". As shown, t e oscillating means comprises the yfollowing mechanism: 16 is a longitudinal`drive shaft mounted in suitable bearings on the headstock casting. This drive shaft is provided with tight and loose belt pulleys 17ll and 18. For shiftin the belt on these pulleys there is provide a manually operable shifting lever 19. Secured to the drive shaft is a pinion 21I meshin with an idler gear 25 mounted on a stu 26, Gear 25* meshes with a gear 27* secured to a longitudinal shaft 20"L mounted in sultable bearings in the' headstock casting. Preferably the pinion 21l is interchangeable with other similar pinions havin diferent numbers of teeth, the stud 26I ing adjustable cillatory movement.

to the s aft 20a is a cam 28. 30l is a lever pivoted to the headstock casting at 29* and provided with a roller 31l engaging the cam 28, A lever 32* is positioned above the lever 30'L and is connected with the bushing 107. Adjustable along the lever 332*l is a lug 33 adapted to be secured in adjusted posltion by means of the screw 34. A spring 35 presses downwardron the lever 32, the spring being adjustable by means df the threaded sleeve 36. It will be seen that as the shaft 20n is rotated the bushing 107 will be oscillated to a greater or less extent in accordance with the adjustment of the lug 33. As shown in Fi 16 the roller 31 is in engagement with t e lowest part of'the cam 28a and the levers 30* and 32l are arallel. It is therefore possible to cha t e position of the lug 33 without changing therelative position of the axis of the spindle 14".

The center 10 of the tailstock is carried by an oscillatory spindle which is prefera ly in the form of a segment 37, The segment 37n is mounted upon the main tail- Stock casting which is providedwith a semicylindrical recess adapted to receive it- The segment 1s cprovided at its ends with semicircular un ercut rabbets and semi-circular glbs 38 and 39* secured to the tailstock casting and fitting the rabbets'hold the segment 1n place without interfering with os- Preferably,ras shown 1n Fig. 17 the segment 37 extends through only a Vlittle more than 180, th'us leaving the space beyond the axis substantially unobstructed and adapted to be occupied by the grinding wheel when necessary.

T e center 10 is preferabl connected with the oscillabo segment 3 by means of a slide 40 to w ich the center is rigidly secured. The center is eccentricall posltloned with respect Ato the axis of t e segment, the eccentricity being the same in extent and position as the' eccentricity of the center 9 with respect to the axis of 'the bushin 107. The slide is longitudinally movab e with respect to the segment and is controlled by a lever 46 pivoted to the tailstock casting at 108. Also mounted on the pivot 108 is a hand lever 109. Mounted between thse two levers is a suitable friction element 110. Because of the :frictional engagement between the two levers the hand lever 109 can be used to transmit power to move the center 10 toward the headstock. As soon as the reamer is engaged further movement of the lever 46'L is prevented and additional movement of the lever 109 causes a cam block 111 carried thereby to engage a roller 112 carried by a lever 1 13. At the other end of the lever is a screw 114, and

los

when the lever is moved by the cam block 111 this screw is pressed a inst an annular surface on the lever 46 thus locking the lever in adjusted position. Preferably the connection between the lever 4:6* and the slid e 40 com rises a rod 42* and a coil spring 41, requently the grinding takes lace at such a rapid rate that the reamer 1s heated, expansion taking place and tending to cause undue pressure and frictionat the centers. The spring permits the center 10 to move backward slightly to compensate for ex ansion. k f

For osci ating the segment 37* there is provided a mechanism similar to that rovided for oscillating the bushing 107. e shaft 20 is exten ed to engage suitable bearins in the tailstock casting). Connected with t e shaft is a collar or ushing provided with a cam 47. This cam bushing is splined to the shaft so as to permit' the tailstock to be adjusted longitudinally with respect to the headstock. Pivoted to the tailstock casting at 48% is a lever 4:9a provided with a roller 50 engaging'the cam 47. Secured to the segment 37"is \a lever 51* which carries a lug 52 V-shaped at its bottom and en a 'ng the lever 49a. The lug is adjustab e` ongitudinally of the lever and can be held in adjuste position by means of a screw 53". A spring 54 presses downward upon the lever 51", the pressure of the spring being adjustable by means of the threaded sleeve 55. It will be seen that b means of this mechanism the segment 3;* will be oseillated as the shaft 20 and the cam 47* are rotated, the extent of oscillation being adjustable by changing the position of the lug 52, t

As shown in Fi 17 the roller 50 is in engagement with the lowest part of the cam 47 and the levers 49* and 51 are parallel. It is therefore possible to change the position of the lug 52 without changing the relative position of the axis of the segment 37". j

The levers 49* and 51 are resectively similar in length and position to t 30*l and 32 and the two cams 28 and 47* are similar in shape and in osition on the shaft 20". Therefore when t e lugs 33 and 52* are similarly positioned the two centers 9 and 10L are oscillated in unison and to the same extent. Preferably, as indicated in Fig. 14, suitable marks are plrovided on the levers 32EL and 51 so that t e two lugs 33 and 52a can be readily ositioned so as to obtain the same amplitu e of oscillation for the two centers.

Means are provided for rotating a reamer mounted on the centers 9 and 10n and in the present embodiment of the invention the reamer is rotated continuously at a uniform rate. The rotation of'the reamer is effected by means of the spindle 14. Se-

e levers,

ieassv orflat face of the reamer shalksllletllh,

form of the driver can be varied as by the form of the shank.

Mounted on the opposite end of the spintdle 14'* is a gear 117 meshing with av inion- 11& secured to the drive shaft 16. t will be seen that by means of this gearing the spindle is continuously rotated, carrying the reamer with it. Obviously, the centers must be moved toward and from the grinding wheel and as many times during each revolution of the reamer as the reamer has teeth- It is for this reason that change-speed gearing is provided for driving the shaft 20. Bfy usin the proper pinion at 21 the speed o the s aft 2OEL may be so determined as to oscillate or reciprocate the reamer the pro er number of times.

e operation of the mechanism shown in Figs. 13 to 18 is similar to that of the mechanism first described except that the reamer is turned continuously instead of intermittent-ly. A detailed description of the operation is unnecessary.

It has heretofore been customary to grind reamers by means of mechanism which oscillated the reamer back and forth about its axis, each tooth being kept iny contact with the grinding wheel until com let/ely ground, and the wheel usually trave ing longitudinally of the reamer. After one tooth was ground then the reamer was indexed and another tooth was ground. This method has the serious disadvantage that because of the wear of the grinding wheel, each tooth is slightly higher than the preceding one, the result being that there is an appreciable ,diilerence between the first tooth and the last tooth. In the effort 'to overcome this diiiiculty to some extent it has been common practice to grind each tooth twice, the irst grinding being to reduce the tooth approximately to size and the second grinding being for the isake of finishing and to remove the inaccuracies in the first rindin arising from the wear of the w eel. uch a double grinding is obviously expensive, and furthermore only partiall eliminates the inequalities of the teeth. n the use of my improved machine and in following my improved method the several teeth'are presented to the wheel in rapid succession, and any wear of the wheel Vaiects all of the teeth uniformly. j

It will be obvious, however, that when the teethl are presented to the wheel in rapid succession as stated, each tooth engaging the wheel but once during a complete revolution of -the reamer, the 'nding cannot ordinarily be finished uring one revolution. Means must usually be provided for eecton successive rcvolutionsof the reamer.

ing a relative feeding or approaching Inove-` ment between the w ieel and the reamer to cause additional metal to be ground away For this purpose I prefer to provide a mechanism similar to that shown in my reissued Patent 13,930 already referred to. This mechanism comprises means for moving the grinding wheel toward and away from the reamer supporting devices. As illustrated in Figs. 19 to 26 the grinding wheel 2 is mounted on a shaft 119 rotatable in'bearings forming parts of a support 120. The support 4120 is mounted on a carriage 121 which in turn is mounted on a main frame 122 which also carries the aforesaid bed 53. Mechanism for moving and controlling the carriage 121 and the grinding wheel comprises an auxiliary carriage 123 having movement in a direction transverse to that of the carriage 121. The said carriages are so constructed and arranged that as the carriage 123 is moved longitudinally in one direction or the other a suitable transverse movement is imparted to the carriage 121' and to the grinding wheel 2 supported thereon. A lug 124 is connected rigidly to the carriage 121 and has sliding contact with a cam fpiece 125 upon the carriage 123.- The face o the member 125 in contact with the lug 124 is so shaped that for a given motion of the carriage 123 a desired motion will be imparted to the carriage 121. Y

or the (purpose of varying the relative position an l movementl of the two carriages the member 125 is pivotally mounted and has a suitable adjusting means coacting therewith. The afhusting means comprises a screw 126 threaded into a block 127 upon the carriage 123, the tapered end of the screw bearing upon a sultably shaped surface of the cam 125. AS the screw is turned the position of the cam faces u on the member 125 will be varied relative y to the carriage 123 upon which the member 125 is carried. Also carried upon the carriage 121 is a roller 128 and a second cam piece 129 is fixed upon the carriage 123. The'roller 128 and the cam piece 129 contact with each other at certain times in order to control the movement of the carriage 121 with respect to the carriage 123.

The carriage 123 is provided with a member for engaging an actuating means which serves to move and control the carriage 123 and thereby the carriage 121 and the grinding wheel 2. The said member is a roller 130, which is in engagement with a cam 131 mounted upon a rotatable shaft 132. The cam has surfaces 133, 134 and 135 shown in Fig. 24 and in dotted lines in Figs. 22 and 23) suitably shaped to impart' movement to the carriage 123. The cam member 131 is adjustable upon the shaft 132, thus serving to adjustthe position of the car- `ringe 123 may be regarded as bein riage 123. The adjusting means comprises a screw thread on the shaft 132 with which the member 131 has threaded engagement, and lock nuts 136 for holding it in its adj usted position.

The driving and controlling means comprises a belt pulley 137 connected by bevel gearing 138 to a shaft 139. Upon the shaft is a worm 140 in mesh with a Worm wheel 141 upon a shaft 142. A gear 143 upon the other end of the shaft 142 meshes with an intermediate gear 144 which in turn meshes with a ar 145 upon the shaft 132. `One end of tie shaft 139 is journaled in a lug upon a. sleeve 146 loosel mounted in the main shaft of the machine, and the other end in a bearing 147 pivotally mounted upon a lever 148 which is in turn pivotally mounted at 149 upon the machine frame. By this construction the shaft 139 may, by the, action of the lever 148, be dropped at one end so that the worm which it carries falls out of mesh with the gear. A suitable pin-andslot connection 150 is provided for limiting the movement of the lever 148. Fixed upon a shaft 151 suitably mounted on the frame of the machine is a lever 152 pulled by a spring 153. Fixed also upon the shaft 151 is a hook 154 which is adapted to engage with a lug 155 upon the lever 148. An arm 156 fixed to the lever 152 is connected by a link 157 to a lever 158 having at its free end a friction roll 159 located in the path of the lug 160 upon a disk 161 carried upon the shaft 132.

lVhen a reamer has been mounted L`on the centers and set in motion in the way already described. the other arts of the machine operate in the following manner, it being understood that the pulley 137 is constantly rotated. Initially. the hook 154 is out of engagement with the lug 155 and the lever 148 is at its lowermost position holding the worin 140 out oiengagement with the worm wheel 141. The operator lifts the lever 143, and the hook 154. yielding against the spring 153. snaps into position beneath the lug. The shafts 142 and 132 are thus caused to rotate.

The carriage 121 and the auxiliary call;-

su stantially in the posltlons shown in 41g'. 22. The roller 130. by the rotation of the shaft 132. rides along the first steep portion 162 of the ram 131, moving the carriage 123 quickly to the left. The lug 124 also rides up the first steep incline 163 upon the cam surface of the member 125. thus givingrt'he carriage 121 together with the grinding wheel 2 and other parts. a relatively quiet idle movement toward the reamer. ie roller 13() Vis now in contact with the slightly inclined cam surface 133 on the cam 131 and slowly but positively'or unyieldingly moves the carriage 123 toward the left.

l able sto During substantially all of this movement the lug 124 is in contact with the next inclined face 164 of the cam piece 125, which has a very small degree of inclination and is slowly and positively moving or feeding the wheel toward the reamer to kee the wheel and the reamer in operative relation as the reamer is ound. The extent and speed of this fee lng movement are determined by the shape of the cam surfaces and by the adjustment of the screw 126. Referring especially to Fig. 24, it will be noted that the cam surface 133 extends into the cam surface 134, which is straight and therefore allows the carriage 123 to remain stationar as the member 131 rotates. There is there ore, no approaching or feeding movement of the carriage and the grinding wheel while the roller 130 is traveling along the surface 134. Preferably, in order to positivel and definitely limit the approaching or eeding movement of the carriage and the wheel, there is provided an adjustcomprising a screw 165 threaded into a ug 166 fixed to the carriage 121. One face of the screw 165 is adapted to contact with a suitable face 167 carried upon the frame of the machine. This additional limiting means acts when there is any spring or play in the work or in the connected parts between the wheel 4and the devices for controlling its movement.

It will be understood that after the approachin or feeding movement is stopped the grin ing wheel and the reamer continue to turn and a supplemental grinding of the reamer is effected to remove any unevenness that may be due to the vibration or springin of the various supporting elements. his sup lemental grinding. continues during at east one complete revolution of the reamer.

As the shaft 132 continues to rotate, the roller 130 comes into contact with the cam piece 135 and the carriage 123 is given a relatively quick! transverse movement to ward the left. At substantially the same time the roller 128 upon the carriage 121 comes into contact with the cam piece 129 on the carria 123 and the carriage 121 is thus moved Eckward, carrying the rinding wheel away from the work; t will thus be seen that the separation of the wheel and the work occurs at a definite period after the approaching movement has ceased. At about this time the lug 160 upon the disk 161 engages the roller 159 on the lever 158. The lever 158 is moved iu a counter-clockwise direction and hy means- 0f the link 157 serves to move the level' 152 in the same direction and to turn thc shaft 151. As theshaft moves. the hook 154 releases the in 155. and permits the lever 148 to drop, t ius releasing the worm 14() from engagement with the fworm wheel 141.

Then the operator removes the reamer which has been ground and a new one is put in place and the machine is ready for further operation in the way described.

In or er to provide for grinding the reamers accurately to an desired size, means are preferably provi ed whereby the wheel support 130 may be adjusted along the carriage 121. This means comprises a rotatable screwthreaded rod 168 rotatable in a 4block 169 upon the car-ria 121 and threaded into a lug 170 upon t e support 120. Suitable means are provided for rotating the threaded rod 168 through any desired angle, this means as shown being a micrometer-head 171.

Usually when a broad-faced wheel is used as shown in Fig. 1, it is found necessary or at least desirable to construct the wheels in a plurality of sections as shown. In order that there may be no unevenness of grinding at the division planes between the sections, provision is made for effecting a relative transverse movement between the wheel and the reamer. It is immaterial whether the movement is effected by moving the work orlby moving the grinding wheel, but in the drawings, mechanism is shown for moving the work. The bed 3 is so mounted on the main frame 122 as to be capable of lon itudinal movement. Located adjacent the ed is a cam member 172 mounted on the aforesaid shaft 142. The cam member 172 has in its periphery an undulatory cam groove 173 which co-acts with a roller 174 carried by the bed. It will be seen, therefore, that when the shaft 142 and the cam member 172 are rotated, the bed 3 to ether with the headstock and tailstock an other parts mounted thereon, will be given a reciprocatory or vibratory movement. The said movement serves to insure uniform grinding along the entire length of the reamer and may also serve to permit the grinding wheel to act on a reamer iaving a length somewhat greater than the width of the wheel.

From the foregoing description, it will be clear that in addition to providing a new and useful machine, I have also provided a new and useful method or process for grinding reamers. The reamer is simultaneously turned and reciprocated toward and from the grinding wheel in such a way that the proper relief is obtained, the wheel engaging each reamer tooth but once during each revolution of the reamer. Preferably the wheel engages theV reamer throughout its entire length and preferably there is effected av relative feeding movement between the reamer and the wheel whereby additional grinding of the teeth is effected at each revolution of the reamer. lVhen the reamer teeth are unevenly spaced, the turning is effected in such a way as to pre- 

